Mac/Lib/quietconsole.py

   1 """quietconsole - A module to keep console I/O quiet but dump it when needed"""
   2 import types
   3 import sys
   4
   5 class _PseudoStdin:
   6         def __init__(self, stdouterr):
   7                 self.keep_stdin = sys.stdin
   8                 sys.stdin = self
   9                 self.keep_stdouterr = stdouterr
  10
  11         def __del__(self):
  12                 self.keep_stdin = self.keep_stdouterr = None
  13
  14         def _revert(self):
  15                 """Return to old state, with true stdio"""
  16                 if self.keep_stdin == None:
  17                         return
  18                 sys.stdin = self.keep_stdin
  19                 self.keep_stdin = None
  20                 self.keep_stdouterr._revert(1)
  21                 self.keep_stdouterr = None
  22
  23         def read(self, *args):
  24                 self._revert()
  25                 return apply(sys.stdin.read, args)
  26
  27         def readlines(self, *args):
  28                 self._revert()
  29                 return apply(sys.stdin.readlines, args)
  30
  31         def readline(self, *args):
  32                 self._revert()
  33                 return apply(sys.stdin.readline, args)
  34
  35         def close(self):
  36                 self._revert()
  37                 sys.stdin.close()
  38
  39 class _PseudoStdouterr:
  40         def __init__(self):
  41                 self.keep_stdout = sys.stdout
  42                 self.keep_stderr = sys.stderr
  43                 sys.stdout = sys.stderr = self
  44                 self.data = []
  45
  46         def __del__(self):
  47                 self.keep_stdout = self.keep_stderr = None
  48
  49         def _revert(self, dumpdata=0):
  50                 if self.keep_stdout == None:
  51                         return
  52                 sys.stdout = self.keep_stdout
  53                 sys.stderr = self.keep_stderr
  54                 sys.keep_stdout = self.keep_stderr = None
  55                 if dumpdata and self.data:
  56                         for d in self.data:
  57                                 sys.stdout.write(d)
  58                 self.data = None
  59
  60         def write(self, arg):
  61                 self.data.append(arg)
  62
  63         def writelines(self, arg):
  64                 for d in arg:
  65                         self.data.append(arg)
  66
  67         def close(self):
  68                 self.keep_stdout = self.keep_stderr = self.data = None
  69
  70 beenhere = 0
  71
  72 def install():
  73         global beenhere
  74         if beenhere:
  75                 return
  76         beenhere = 1
  77         # There's no point in re-installing if the console has been active
  78         obj = _PseudoStdouterr()
  79         _PseudoStdin(obj)
  80         # No need to keep the objects, they're saved in sys.std{in,out,err}
  81
  82 def revert():
  83         if type(sys.stdin) == types.FileType:
  84                 return  # Not installed
  85         sys.stdin._revert()
  86
  87 def _test():
  88         import time
  89         install()
  90         print "You will not see this yet"
  91         time.sleep(1)
  92         print "You will not see this yet"
  93         time.sleep(1)
  94         print "You will not see this yet"
  95         time.sleep(1)
  96         print "You will not see this yet"
  97         time.sleep(1)
  98         print "You will not see this yet"
  99         time.sleep(1)
 100         print "5 seconds have passed, now you may type something"
 101         rv = sys.stdin.readline()
 102         print "You typed", rv
 103
 104 if __name__ == '__main__':
 105         _test()
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